Conventionally, human hair and artificial hair (modacrylic fiber or polyvinyl chloride fiber) have been used in hair productions such as a hairpiece, a hair wig, a hair extension, a hair bundle, and a doll hair. However, it gradually becomes difficult to obtain the human hair, and the artificial hair is increasingly important instead. Although the modacrylic fiber has been widely used as a raw material of the artificial hair due to the advantage of being flame retardant, it is insufficient in terms of the heat-resistant temperature. In recent years, a polyester fiber that includes polyester as the main component (typified by polyethylene terephthalate with excellent heat resistance) has been proposed as an artificial hair fiber. However, the polyester fiber itself has a high gloss, a hard touch, and a squeaky (waxy) feeling, and therefore can cause a problem when used as a raw material of the artificial hair. For this reason, some methods for improving the luster and texture of the polyester fiber have been proposed. In general, the fiber surface is made rough to improve the luster or to change the texture. For example, titanium oxide fine particles are added to deluster the polyester fiber. However, it is well known that this method merely removes the gloss from the fiber surface and leads to poor color development. Another technique has been proposed in which the polyester fiber including inorganic fine particles is alkali-etched so that particular projections and depressions are formed in the fiber surface (Patent Document 1). In this technique, although a high hyperchromic effect can be obtained by the uneven fiber surface, the luster is reduced. Thus, it is difficult to achieve the hyperchromic effect while maintaining the luster. Moreover, a method for mixing fine particles with a polymer matrix has been proposed. However, this method raises the problems of the aggregation of the fine particles in the polymer, an increase in viscosity of the polymer melt or solution, the decomposition and degradation of the fine particles and the polymer during the manufacturing process, a decrease in the physical properties of the formed fiber, etc.
In addition to the above problems, the conventional artificial hair has low antibacterial properties. If the antibacterial properties are low, bacteria can generate and proliferate while the artificial hair is worn for a long time or stored after being used.
On the other hand, a method for coating a resin sheet or the like with regenerated collagen or regenerated collagen particles, which are different from those produced by the method of the present invention, has been proposed (Patent Documents 2 to 4). However, this method is intended to give a leather texture rather than to improve the antibacterial properties.
Patent Document 1: JP S55 (1980)-107512 A
Patent Document 2: JP S62 (1987)-34880 B
Patent Document 3: JP H3 (1991)-255200 A
Patent Document 4: JP H9 (1997)-273080 A